I agree with what everyone has been telling you. I'm also 3.5 out of my last surgery and every time I try to do too much, I pay for it in a big way. I had a "loop" ileostomy in 2017, now they removed the colon and revised it to an "end" ileostomy. It's hard to be patient but I do realize it takes time for our body to heal.
With regard to wearing the pouch vertical/horizontal... I use the Coloplast two-piece and actually put it on at an angle so it is more comfortable since I'm so short waisted (it's still easy to empty into the toilet). I prefer the two piece for a couple reasons: I can change the bag without changing the entire appliance - if I'm going somewhere, it just makes me feel cleaner to know it's fresh. Also I try to wear the belt so have the flange straight and only turn the pouch... know what I mean?
Good luck to you, hang in there and take the time you need to heal --> I'm with ya, and I'll even try to practice what I preach